Novel methodology for analysis and evaluation of SAFT-type equations of state

The current study demonstrates that the pure-component critical temperatures generated by SAFT-type equations of state (EoS) are independent of the hard-core diameter (σ). This remarkable feature leads to the development of a simple tool, called a global map, for a comprehensive investigation of the sophisticated SAFT-models under consideration. Practically, a net of critical isotherms in the m (chain length), u /k or ε/k (segment energy parameter) plane is plotted not only for the ordinary but also for the additional unrealistic critical temperatures. Such a map makes it possible to check whether unrealistic phase equilibria will be predicted by the considered SAFT model. In addition, the present study points out that the numerical pitfalls encountered at ambient temperature with the CK-SAFT and the PC-SAFT EoS can be eliminated by refitting the values of the universal constants.